Where did EBP originate?
Based on evidence-based medicine (i.e. not basing decisions on guesses or assumptions, instead basing them on research, ensuring patient care is derived from scientific evidence on what works best
Example of tradition-based police practices which EBP seeks to change
Having as many officers on duty at 4AM as there are at 4PM, even though scientific evidence suggests that there are more people out at 4PM and therefore more crime
Anecdotal evidence vs. Rigorous research
- Anecdotal evidence based on experience, research based on studies, experimentation and data collection
- Some police agencies believe that simply employing crime analysts = EBP, when it is not
Defining EBP (Telep & Somers, 2019)
1) Have officers heard of it?
2) If so, how do they describe it?
3) If so, do definitions vary by rank?
Survey design (Telep & Somers, 2019)
- 3 samples across the US (1st sample = Sacramento [CA], Richmond [VA], Reno [NV], and Roanoke County [VA]; 2nd & 3rd samples = Oregon)
- Asked 2 questions w/ identical wording: “Have you heard of EBP” and “How would you define it”
Results (Telep & Somers, 2019)
- Variablility in familiarity w/ EBP and key terms used to describe it
- Only 5% provided completely accurate definition
- 30% gave incorrect definitions
- Positive relationships b/t rank & accuracy of definition, as well as higher education & accuracy
Description of Simpson research regarding officer attire
- Looked at how uniforms of Irvine PD altered public perception
- Took photos of officers in alternative uniforms and showed them to participants in a blind study to measure their perceptions of the officers in multiple different capacities
Results of Simpson uniform research
- Found uniforms did have significant effects on public perception
- Public gravitated towards officers in high-vis vests
- Elements that induced negative perception = black gloves, sunglasses, batons
- Baseball caps = no effect
- Tactical vests = mixed perception (officer seen as more aggressive, yet respectful and authoritative
Aftermath of Simpson uniform research
- Officers in Irvine now wear more high-vis vests and baseball caps
- Black gloves removed, now use different colors of gloves
Description of Simpson vehicle research
Experiment performed same sort of test as the clothing except with 3 variations of cars: a marked vehicle, an unmarked vehicle, and a civilian vehicle (also had 2 variations of marked vehicles; black and white & pure white w/ blue stripe)
Results of Simpson vehicle research
- Participants always prefer marked vs. unmarked cars (preferred black and white ones vs. white and blue ones)
- Irvine PD changed their cars’ colors as a result
Description of Constable Scarecrow experiment
- Fake cardboard cutout of cop posted at strategic positions to slow down traffic
- Based around concerns of trafic conditions and traffic-related deaths (collisions = leading cause of death for people aged 15-29, 8th leading cause of death worldwide)
Methods of Constable Scarecrow
- Placed at Arterial (Highways & connective roads) and Residential (Suburbs)
- 5-week cycle (Weeks 1 & 5 = Radar device only; Weeks 2-4 = Cutout & radar device
Results of Constable Scarecrow
- Cutout = Decreases in speeders with it present (Negative coefficient)
- Arterial routes = Sharp decrease in speeding at first; gradually ramped up again over time
- Residential routes = No significant changes
- CS still used by Coquitlam to this day; other areas in Canada also employing similar strategies
